It is the purpose of this study to synthesize procollagen in cell- free protein synthesizing systems derived from heterologous sources, from animal cells (Krebs II mouse ascites tumor) and from a plant extract (wheat germ). Collagen messenger RNA from chick embryo calvaria (Type I collagen) and mouse chondrosarcoma (Type II collagen) are being examined. This study is divided into several portions. 1. Comparison of ribosomes from various sources in their ability to support collagen synthesis. 2. Search for and fractionation of collagenous tissue specific tRNAs, particularly tRNAs for glycine and proline. 3. Examination of protein synthesizing factors such as collagenous tissue specific initiation factors and their role in translational control of collagen synthesis. 4. Evaluation of the cell-free synthetic collagenous product. 5. Purification and characterization of the collagen specific messenger RNA as to size, base composition and oligonucleotide fingerprint pattern following nuclease digestion.